Health Check

Monitor environment variable health in production with built-in health check utilities.

Quick Start

import { healthCheck, createHealthEndpoint } from "nevr-env";

// Check health programmatically
const result = healthCheck({
  server: envSchema.server,
  plugins: [postgres(), stripe()],
  runtimeEnv: process.env,
});

console.log(result.status); // "healthy" | "degraded" | "unhealthy"

Express Integration

import express from "express";
import { createHealthEndpoint, postgres, stripe } from "nevr-env";

const app = express();

// Add health check endpoint
app.get("/health/env", createHealthEndpoint({
  server: {
    DATABASE_URL: z.string().url(),
    NODE_ENV: z.enum(["development", "production"]),
  },
  plugins: [postgres(), stripe()],
}));

app.listen(3000);

Next.js API Route

// app/api/health/env/route.ts
import { createHealthEndpoint, postgres } from "nevr-env";

export const GET = createHealthEndpoint({
  server: envSchema.server,
  plugins: [postgres()],
});

Response Format

{
  "status": "healthy",
  "timestamp": "2026-02-05T10:30:00.000Z",
  "summary": {
    "total": 8,
    "valid": 8,
    "invalid": 0,
    "missing": 0
  },
  "variables": [
    {
      "name": "DATABASE_URL",
      "valid": true,
      "present": true,
      "source": "PostgreSQL",
      "sensitive": true
    },
    {
      "name": "STRIPE_SECRET_KEY",
      "valid": true,
      "present": true,
      "source": "Stripe",
      "sensitive": true
    },
    {
      "name": "NODE_ENV",
      "valid": true,
      "present": true,
      "source": "custom",
      "sensitive": false
    }
  ]
}

Status Codes

Status	HTTP Code	Description
healthy	200	All variables valid
degraded	503	Some optional variables missing
unhealthy	503	Required variables invalid/missing

Options

healthCheck({
  // Schema definitions
  server: { ... },
  client: { ... },
  shared: { ... },
  plugins: [...],
  
  // Runtime environment source
  runtimeEnv: process.env,
  
  // Mark additional keys as sensitive (masked in output)
  sensitiveKeys: ["CUSTOM_API_TOKEN"],
  
  // Include non-sensitive values in response (for debugging)
  includeValues: false,
});

Kubernetes Liveness/Readiness Probes

# deployment.yaml
spec:
  containers:
    - name: app
      livenessProbe:
        httpGet:
          path: /health/env
          port: 3000
        initialDelaySeconds: 10
        periodSeconds: 30
      readinessProbe:
        httpGet:
          path: /health/env
          port: 3000
        initialDelaySeconds: 5
        periodSeconds: 10

Monitoring Integration

import { healthCheck } from "nevr-env";

// Periodic health check with alerting
setInterval(async () => {
  const result = healthCheck({
    server: envSchema.server,
    plugins: [postgres()],
    runtimeEnv: process.env,
  });
  
  if (result.status === "unhealthy") {
    // Send alert
    await slack.send({
      channel: "#alerts",
      text: `⚠️ Environment unhealthy: ${result.summary.invalid} invalid, ${result.summary.missing} missing`,
    });
  }
  
  // Send metrics
  metrics.gauge("env.health.valid", result.summary.valid);
  metrics.gauge("env.health.invalid", result.summary.invalid);
}, 60000);